Multifocal community-acquired MRSA infection: a rare case involving urinary tract, bloodstream, chest wall, and pleura.

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital- and community-acquired multidrug-resistant infections. Typical infection sites include the skin, respiratory tract, and bloodstream. This report describes a rare case of multifocal community-acquired MRSA (CA-MRSA) infection simultaneously causing urinary tract infection, bacteremia, chest wall abscess, and empyema.

CASE PRESENTATION: A 51-year-old man with newly diagnosed diabetes mellitus on admission was admitted with a 2-week history of right posterior chest wall pain and a mass. Imaging showed soft tissue swelling in the right chest wall and pleural effusion. Urine and blood cultures grew MRSA. The patient was treated with linezolid and levofloxacin, insulin therapy, and nutritional support, and the chest wall abscess was incised and drained. Pus culture and targeted next-generation sequencing (tNGS) confirmed MRSA infection with mecA and SCCmec antimicrobial-resistance genes. The patient recovered and had no recurrence during 2 months of follow up.

DISCUSSION: This case reveals that CA-MRSA can cause disseminated infections without obvious predisposing factors such as catheterization or trauma. Hyperglycemia and HHV-6 suggest impaired immune function. Combination antimicrobial therapy and surgical intervention were effective in the short term; however, the short follow-up period limits assessment of long-term outcomes. tNGS played a crucial role in identifying antimicrobial-resistance mechanisms.

CONCLUSION

CA-MRSA can cause multifocal infections in immunocompromised patients. This rare case, with simultaneous urinary, bloodstream, chest wall, and pleural involvement, highlights the importance of early recognition, individualized therapy, and confirmation of resistance using tNGS. The outcome demonstrates the short-term effectiveness of this combined approach.